1. Field of the Invention
This invention generally relates to digital communications and, more particularly, to a system and method for creating virtual subchannels, within a 10 gigabit per second (10G) virtual channel of a 40G Ethernet network.
2. Description of the Related Art
FIG. 1 is a schematic diagram of a wave division multiplexed (WDM) module interfacing between 40G fiber and a media access control (MAC) module (prior art). The 40G link may be in other forms including 4-lane backplane link, 4-lane copper link, or 4 separate (not WDM) optical links. In 40G applications, such as those based upon the emerging IEEE 802.3ba standard, 4 lanes or virtual channels of 10.3125 Gbps (10G) are supported. The interface between devices in this format is known at XLAUI. However, not all MAC modules are capable of supporting rates of 10.3125 Gbps. There is no means explicitly described in the 802.3ba standard to deinterleave a 10G virtual channel into two lanes and interleave at the other end. Even if the 10G channel could be deinterleaved, there is no disclosed means of compensating for potentially large skews resulting from buffering at the transmitter, differences in medium electrical length, and buffering at the receiver.
It would be advantageous if 10G virtual channels in a 40G Ethernet network could be simply deinterleaved into 5G subchannels, and reassembled into 10G channels on the receive side, without changing the specification or adding overhead to the signal.